Positive Fitness Research Articles

A simple model and rules for the evolution of microbial mutualistic symbiosis with positive fitness feedbacks

The evolution of microbe-microbe mutualistic symbiosis is considered to be promoted by repeated exchanges of fitness benefits, which can generate positive fitness feedbacks ('partner fidelity feedback') between species. However, previous evolutionary models for mutualism have not captured feedback dynamics or coupling of fitness between species. Here, a simple population model is developed to understand the evolution of mutualistic symbiosis in which two microbial species (host and symbiont) continuously grow and exchange fitness benefits to generate feedback dynamics but do not strictly control each other. The assumption that individual microbes provide constant amounts of resources, which are equally divided among interacting partner individual, enables us to reveal a simple rule for the evolution of costly mutualism with positive fitness feedbacks: the product of the benefit-to-cost ratios for each species exceeds one. When this condition holds, high cooperative investment levels are favored in both species regardless of the amount invested by each partner. The model is then extended to examine how symbiont mutation, immigration, or switching affects the spread of selfish or cooperative symbionts, which decrease and increase their investment levels, respectively. In particular, when a host associates with numerous symbionts without enforcement, neither mutation nor immigration but rather random switching would allow the spread of cooperative symbionts. Examples using symbiont switching for evolution would include large ciliates hosting numerous intracellular endosymbionts. The simple model and rules would provide a basis for understanding the evolution of microbe-microbe mutualistic symbiosis with positive fitness feedbacks and without enforcement mechanisms.

Physical Fitness and Self-Perception in Adolescents: A Public Health Perspective

Adolescence is a critical period for physical and psychological development. The relationship between physical fitness and self-perception, particularly in the context of adolescents, has garnered significant attention due to its implications for long-term health outcomes. This article explores the intersection of physical fitness and self-perception in adolescents, emphasizing the role of physical activity in shaping self- esteem, body image, and mental health. From a public health perspective, promoting physical fitness in this age group can contribute not only to improved physical health but also to better psychological well-being. The article discusses interventions, policy initiatives, and practical recommendations to support adolescents in developing positive physical fitness habits and fostering healthy self-perception.

A predictive model based on quantitative fecal immunochemical test can stratify the risk of CRC in an organized screening program

A significant number of post-faecal immunochemical test (FIT) colonoscopies in European organized colorectal cancer (CRC) screening programs are performed beyond the recommended 31-day threshold due to overburdened colonoscopy services. We aimed to develop a simple predictive model to stratify CRC risk of FIT+ patients. In a cohort of screenees undergoing colonoscopy following a positive ( ≥ 20μg Hb/g. feces) OC-sensor FIT result between 2004 and 2019, we derived and validated logistic regression-based models including variables independently associated with CRC and advanced neoplasms. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported. Overall, 40,276 patients (46% female, mean age 66+4 years) undergoing post-FIT colonoscopy were included. Variables independently associated with CRC were age ≥70 years (OR 1.20, 95%CI 1.03-1.40), male sex (OR 1.23, 95%CI 1.11-1.37), f-Hb level (50 to 199 μg/g.: OR 2.84, 95%CI 2.47-3.27; ≥200 μg/g: OR 6.91, 95%CI 5.99-7.98), and first round of FIT (OR 1.53, 95%CI 1.35-1.73). The discriminative ability of the model was good (AUROC 0.75, 95%CI 0.73-0.77) in the validation cohort. Applying the model would lead to over two thirds decrease in delayed CRC diagnoses, considering various scenarios of timely colonoscopy scheduling after FIT+. We derived and validated a predictive model for risk stratification of patients with positive FIT in a large CRC screening cohort. Applying our model in screening practice would allow policy makers to effectively prioritize FIT+ individuals based on the risk of CRC, allowing to substantially reduce the rate of delayed CRC diagnosis.

Impact of the COVID-19 pandemic on adherence to diagnostic colonoscopy after a positive non-invasive screening test for colorectal cancer in two Indiana healthcare systems

ObjectiveTo describe trends in the use of non-invasive tests (NIST) and the interval between a positive NIST and diagnostic colonoscopy. MethodsUsing a retrospective time-trend design, we examined medical records of patients within two large Indiana integrated healthcare systems who had a positive NIST between January 2019 and June 2021 and quantified the proportion of patients who had not completed colonoscopy within 60, 90, and 180 days to determine the interval between NIST result and diagnostic colonoscopy in days. ResultsOf 1379 patients with positive NISTs, 930 (68 %) underwent diagnostic colonoscopy during the 30-month study timeframe. Median time to colonoscopy completion was significantly longer in 2020 compared to 2019 (50 vs. 37 days, p < 0.01) and 2021 (46 days, p = 0.06). The proportion of patients completing colonoscopy within 90 days of a positive FIT in 2019, 2020, and 2021 were 79 %, 83 %, and 72 %, respectively (p = 0.63), and were 86 %, 78 %, and 84 %, respectively, after positive FIT/DNA (p = 0.07). Median time to diagnostic colonoscopy completion was significantly longer in 2020, likely due to the COVID-19 pandemic. ConclusionsStudies of outcomes in those who declined or delayed colonoscopy in 2020 are needed to estimate the potential subsequent colorectal cancer disease burden.

S2929 A Rare Case of Colonic Extranodal Marginal Zone Lymphoma Presenting as a Positive FIT Test

S2929 A Rare Case of Colonic Extranodal Marginal Zone Lymphoma Presenting as a Positive FIT Test

Can everyone get interesting jobs? Estimating interest fit across gender, ethnicity, and education

AbstractAlthough research and policy efforts have attempted to “even the hiring playing field” and progress equal opportunities, systemic employment patterns based on gender and ethnicity remain prevalent. An unexplored avenue of diversity, equity, and inclusion efforts is the degree to which all people can obtain jobs that fit their interests. The present study used a large, diverse sample of over 250,000 American employees to estimate the average vocational interest fit that people have with their jobs and differences in fit across race/ethnicity, gender, and education. Overall, employees showed moderate positive vocational interest fit with their jobs, with an average profile correlation of .20 between person and job interests. There were small gender differences in vocational interest fit favoring men, especially White and Hispanic men, with minimal differences across other race/ethnicity groups. However, the largest group differences emerged for education, as employees with higher educational attainment showed greater vocational interest fit, particularly among women. Further intersectional analyses added greater nuance to these results, including how various groups achieve vocational interest fit across different types of jobs. Altogether, this work provides important fit benchmark estimates for researchers, counselors, organizational placement, and theory refinement.

Sharp approximation and hitting times for stochastic invasion processes

We are interested in the invasion phase for stochastic processes with interactions. A single mutant with positive fitness arrives in a large resident population at equilibrium. By a now classical approach, the first stage of the invasion is well approximated by a branching process. The macroscopic phase, when the mutant population is of the same order as the resident population, is described by the limiting dynamical system. We capture the intermediate mesoscopic phase for the invasive population and obtain sharp approximations. It allows us to describe the fluctuations of the hitting times of thresholds, which inherit a large variance from the first stage. We apply our results to two models which are original motivations. In particular, we quantify the hitting times of critical values in cancer emergence and epidemics.

Effects of female-specific selection for reproductive investment on male fertility traits.

Despite sharing an autosomal genome, the often divergent reproductive strategies of males and females cause the selection to act in a sex-specific manner. Selection acting on one sex can have negative, positive, or neutral fitness consequences on the opposite sex. Here, we test how female-limited selection on reproductive investment in Japanese quail (Coturnix japonica) affects male fertility-related traits. Despite there being no difference in the size of males' testes from lines selected for high female reproductive investment (H-line) or low female reproductive investment (L-line), in both lines, the left testis had a greater volume of sperm-producing tissue. Since H-line females have a larger left-side restricted oviduct, this suggests a positive genetic correlation between male and female gonad function and that internal testis structure is a target of sexual selection. However, despite H-line males having previously been found to have greater fertilization success in a competitive scenario, we found little evidence of a difference between the lines in sperm number, motility, velocity, length, or the number of sperm that reached the ova. Precopulatory cues and/or the role of seminal fluid in sperm motility may thus be more likely to contribute to the H-line male fertilization advantage in this species.

Landslide Susceptibility Modelling of Central Highland Part of Chaliyar River Basin, Kerala, India with Integrated Algorithms of Frequency Ratio and Shannon Entropy

An integrated landslide susceptibility analysis is carried out for the central highland region of the Chaliyar River Basin in Kerala, India using bivariate statistical methods, namely the Frequency Ratio (FR) and Shannon Entropy (SE). The study addresses the complex nature of landslides, influenced by natural as well as anthropogenic factors, with specific focus on assessing the landslide likelihood of the study area. The methodology involves a systematic approach of collecting the inventory data, identifying various landslide causative factors and developing their corresponding thematic maps, spatial analysis of landslide occurrence and causative factors using GIS software and generation of Landslide Susceptibility Model (LSM) employing FR and SE algorithm, followed by model validation. Various causative factors considered for the study include slope angle, slope aspect, slope curvature, elevation, lithology, drainage density, landuse and landcover (LULC), Topographic Wetness Index (TWI) and Normalized Difference Vegetation Index (NDVI). The FR and SE algorithm enable the spatial classification of the study area into four landslide susceptibility categories namely Low, Moderate, High, and Very High. Validation of both the LSMs was carried out using Landslide Density Index (LDI) and Area Under the Curve (AUC) methods. LDI demonstrate a positive fit for both the models, which is indicative of reliability of the susceptibility predictions of the study area. A slightly higher AUC value of SE model is an indication of a high accuracy rate of SE model over FR model. This research brings out a robust methodology for predicting and identifying the landslide risks of the study area.The outcomes of this study will help in developing effective strategies to manage the landslide hazards in geologically vulnerable areas. Keywords: Landslide Susceptibility, Landslide Conditioning Factors, Frequency Ratio, Shannon Entropy, Landslide Density Index(LDI), Area Under the Curve (AUC)

Transmissible cancers, the genomes that do not melt down.

Evolutionary theory predicts that the accumulation of deleterious mutations in asexually reproducing organisms should lead to genomic decay. Clonally reproducing cell lines, i.e., transmissible cancers, when cells are transmitted as allografts/xenografts, break these rules and survive for centuries and millennia. The currently known 11 transmissible cancer lineages occur in dogs (canine venereal tumour disease), in Tasmanian devils (devil facial tumor diseases, DFT1 and DFT2), and in bivalves (bivalve transmissible neoplasia). Despite the mutation loads of these cell lines being much higher than observed in human cancers, they have not been eliminated in space and time. Here, we provide potential explanations for how these fascinating cell lines may have overcome the fitness decline due to the progressive accumulation of deleterious mutations and propose that the high mutation load may carry an indirect positive fitness outcome. We offer ideas on how these host-pathogen systems could be used to answer outstanding questions in evolutionary biology. The recent studies on the evolution of these clonal pathogens reveal key mechanistic insight into transmissible cancer genomes, information that is essential for future studies investigating how these contagious cancer cell lines can repeatedly evade immune recognition, evolve, and survive in the landscape of highly diverse hosts.

Thick-billed Murres in breeding pairs migrate and overwinter far apart but in similar photic environments

Scheduling between mates in species with long-term pair bonds can be essential for positive fitness. The annual cycle in photoperiod is the primary environmental cue used by many animals to synchronize behavior and physiology among members of a population, and animals that migrate must have similar annual schedules to ensure successful breeding. However, we know little about whether members of mated pairs in migratory species experience similar photic environments across the year, which could allow for synchronization in annual phenology. Here, we used light-based geolocation to estimate positions of mated pairs of Thick-billed Murres (Uria lomvia, a seabird a.k.a. Brünnich’s Guillemot) which bred above the northern polar circle in Greenland. We tested the hypothesis that individuals in mated pairs occur in more similar locations and photic environments than randomly matched females and males. We found no difference in the amount of spatial separation or in the photic environment between mates and randomized heterosexual pairings. In general, the distance between females and males ranged from 1,198.5 km during August to 737.4 km during January. The sexes remained in photic environments with highly correlated photoperiods and moderately correlated times of solar noon in UTC. The spatial separation of, but similar photic environments experienced by, female and male murres regardless of pair status is probably adaptive by facilitating the synchronization of annual schedules between sexes, while allowing individuals in mated pairs the freedom to pursue the best foraging opportunities during migration and overwintering independent of their mate.

Trends in colorectal cancer screening compliance and incidence among 60- to 74-year-olds in China.

Compliance with colonoscopy among elderly individuals participating in colorectal cancer (CRC) screening programs is unsatisfactory, despite a high detection rate of bowel-related diseases. In this study, our aim was to analyze the impact of risk factors on the trends of compliance and detection rates in colonoscopy among high-risk individuals aged 60-74. A retrospective study was conducted on the high-risk individuals aged 60-74 participating in the 2021 CRC screening program in Tianjin, China. Logistic regression analyses, including both univariate and multivariate analyses, were performed to explore the impact of different risk factors on colonoscopy compliance among the high-risk individuals. Besides, the study investigated the influence of various risk factors on the detection rates of bowel-related diseases among the high-risk individuals who underwent colonoscopy. A total of 24,064 high-risk individuals were included, and 5478 individuals received a free colonoscopy, with an overall compliance of 22.76%. Among them, the adenoma detection rate was 55.46%. Males and individuals with a positive FIT had high compliance and detection rates for CRC, advanced adenomas (AA), advanced colorectal neoplasia (ACN), and colorectal neoplasm (CN). Individuals aged 70-74 were associated with low compliance but high CRC, ACN, and CN detection rates. Individuals who reported a history of chronic constipation, bloody mucous, and CRC in first-degree relative showed high compliance but no significantwere associated with the detection rates of CRC, AA, and CN. This study reported several risk factors associated with the screening behaviors for CRC. Patterns and trends in CRC, AA, ACN, and CN compliance and detection rates correlate with risk factors.

Neoplasia detection in FIT positive screening colonoscopies compared with an age-controlled symptomatic cohort: a retrospective review

Colonoscopy following a positive FIT test in an average risk population is effective in reducing CRC incidence and mortality. While lower gastrointestinal symptoms remain a common cause for referral for colonoscopy, symptoms are poor predictors of clinically significant disease. The study was performed to compare neoplasia detection FIT +ve individuals and age-matched symptomatic cohorts. A single centre retrospective observational study was performed including all index colonoscopies performed on patients aged 60-70 from January 2015 to September 2021. Diagnostic yield was reported as adenoma detection rate, SSL detection rate, detection of high risk finding or adenocarcinoma. 8,106 colonoscopies were performed on patients aged 60-70 years. 3,695 (45.6%) originated from screening (FIT +ve). With exclusion criteria applied, 2,640 (59.9%) for screening and 1,767 (40.1%) for symptomatic patients were included. Median age in screening was 65 years (IQR 62-67) and 64 years in the symptomatic group (IQR 62-68), with male predominance in both groups (n=1,536, 58.1%, n=944, 53.4%). There were significant differences in both the ADR (56% vs 26.3%, p&amp;lt;0.01) and the SSLDR (10.4% vs. 8.1%, p=0.05) in the screening cohort compared to the symptomatic group. High risk findings (21.3% vs. 7.5%, p&amp;lt;0.01) were significantly more prevalent in the screening group with a considerably higher colorectal cancer (4.7% vs. 0.9%, p=&amp;lt;0.001) detection rate. FIT based triage significantly outperforms symptom based investigation for individuals in the 60-70 age group. Patients should be preferentially referred to organised colorectal cancer screening. FIT can be performed on symptomatic patients, to identify low risk individuals.

3D Printed Materials for Permanent Restorations in Indirect Restorative and Prosthetic Dentistry: A Critical Review of the Literature.

The objective of this study was to review the scientific evidence currently available on 3D printable materials and 3D printing technologies used for the fabrication of permanent restorations, focusing on material properties that are clinically relevant. A literature search was performed on four databases (MEDLINE/PubMed, Scopus, Cochrane Library, Web of Science) for articles published from January 2013 until November 2023, using a combination of free words: (restorative dentistry OR prosthetic dentistry) AND (3D printing OR additive manufacturing OR rapid prototyping) AND materials. Two reviewers screened titles and/or abstracts of 2.468 unique studies. In total, 83 studies were selected for full-text reading, from which 36 were included in the review. The assessed variables were mechanical properties, reporting in most of the cases positive results, dimensional accuracy and fit, reporting conflicting results with a predominance of positive, aesthetic properties, with positive reports but scarcely addressed, and biological properties, almost unexplored in independent studies. Despite numerous studies with positive results in favor, papers with negative outcomes were also retrieved. Aesthetic and biological properties are conversely still mostly unexplored. There remains a lack of conclusive evidence for viable 3D printable restorative and prosthodontic materials for permanent restorations. Research should be strengthened by defining international standards for laboratory testing and, where pre-clinical data are promising, conducting clinical trials.

Fitness self-presentations on social media and the impact of social support on physical activities.

Social media serves as one of the primary outlets for self-presentation and receiving social support. Even when individuals portray themselves negatively, it might not necessarily be intended for social disapproval. Conversely, positive self-presentation doesn't always guarantee social support. This study examined the relationship between positive and negative fitness self-presentations on social media and the reception of supportive feedback. Additionally, it investigated how social support might influence individuals' self-efficacy, motivation, and participation in physical activities (PA). Participants were fitness app users recruited from a crowdsourcing internet marketplace who had shared their fitness experiences on social media. The results indicated that both types of self-presentation received social support: presenters receiving more social support showed higher self-efficacy for PA. Moreover, fitness posters with higher self-efficacy in PA showed greater motivation for PA. This research suggests that fitness self-presentation allows users to receive social support, fostering confidence and motivation for engaging in PA.

A153 IMPLEMENTATION OF THE CHAMPLAIN REGION GASTROINTESTINAL ENDOSCOPY CENTRAL INTAKE (GICI) PROGRAM

Abstract Background The Champlain region of Ontario is implementing a regional central intake triage program for screening colonoscopy services (FIT+, screening and surveillance indications). The aim of this program is to improve the delivery of regional endoscopy services, so that access to resource-intensive endoscopy procedures can be equitable, timely and evidence-based. We characterized the first phase of implementation of the Champlain Regional GI Central Intake (GICI). Aims The primary objective of this study is to identify program strengths and opportunities for quality improvement. Methods Prospective data was collected from August 1, 2022 to August 31, 2023. Descriptive statistics were analyzed. Discrete data were presented in terms of counts, percentages and means where appropriate. Results 1942 CIP referrals were received during the period of study. 1478(76.1%) referrals were submitted by fax, and 571(29.4%) were for positive FITs. 703(36.2%) referrals were declined, with 374(19.3%) not meeting Cancer Care Ontario (CCO) referral indications, 84(4.3%) being duplicates and 56(2.9%) being symptomatic. Prior to a policy change in March 2023, 23(1.2%) referrals were declined due to incomplete referral forms. 581(29.9%) referrals indicated a preferred physician or hospital site. On average, triage decisions were made within 11.4 hours of receipt of referrals for positive FIT, and 6.8 days for other indications. The average time from FIT positivity to referral receipt at CIP was 20.0 days. In the first quarter of 2023, 75th percentile wait times for colonoscopy were 35 days for FIT positivity, 150 days for symptoms, and 346 days for other screening indications. Conclusions GICI and the use of CCO evidence-based guidance reduces the need for colonoscopy in nearly 20% of referrals. It also decreases physician administrative burdens by eliminating duplicate referrals. Referrals should not be declined due to incomplete forms. Measures to improve timely access to colonoscopy for symptomatic patients should be explored. Most referred patients do not have a preferred physician or hospital site. Further primary care support and engagement is needed to encourage the use of the GICI as well as immediate referral for FIT+ colonoscopy. Funding Agencies None

Interpretation issues with "genomic vulnerability" arise from conceptual issues in local adaptation and maladaptation.

As climate change causes the environment to shift away from the local optimum that populations have adapted to, fitness declines are predicted to occur. Recently, methods known as genomic offsets (GOs) have become a popular tool to predict population responses to climate change from landscape genomic data. Populations with a high GO have been interpreted to have a high "genomic vulnerability" to climate change. GOs are often implicitly interpreted as a fitness offset, or a change in fitness of an individual or population in a new environment compared to a reference. However, there are several different types of fitness offset that can be calculated, and the appropriate choice depends on the management goals. This study uses hypothetical and empirical data to explore situations in which different types of fitness offsets may or may not be correlated with each other or with a GO. The examples reveal that even when GOs predict fitness offsets in a common garden experiment, this does not necessarily validate their ability to predict fitness offsets to environmental change. Conceptual examples are also used to show how a large GO can arise under a positive fitness offset, and thus cannot be interpreted as a population vulnerability. These issues can be resolved with robust validation experiments that can evaluate which fitness offsets are correlated with GOs.

Post-colonoscopy colorectal cancers in a national fecal immunochemical test-based colorectal cancer screening program.

Post-colonoscopy colorectal cancers (PCCRCs) decrease the effect of colorectal cancer (CRC) screening programs. To enable PCCRC incidence reduction in the long-term, we classified PCCRCs diagnosed after colonoscopies performed in a fecal immunochemical test (FIT)-based screening program. PCCRCs diagnosed after colonoscopies performed between 2014-2016 for a positive FIT in the Dutch CRC screening program were included. PCCRCs were categorized according to the World Endoscopy Organization consensus statement into (a) interval PCCRC (diagnosed before the recommended surveillance); (b) non-interval type A (diagnosed at the recommended surveillance interval); (c) non-interval type B (diagnosed after the recommended surveillance interval); or (d) non-interval type C (diagnosed after the intended recommended surveillance interval, with surveillance not implemented owing to co-morbidity). The most probable etiology was determined by root-cause analysis. Tumor stage distributions were compared between categories. 116362 colonoscopies were performed after a positive FIT with 9978 screen-detected CRCs. During follow-up, 432 PCCRCs were diagnosed. The 3-year PCCRC rate was 2.7%. PCCRCs were categorized as interval (53.5%), non-interval type A (14.6%), non-interval type B (30.6%), and non-interval type C (1.4%). The most common etiology for interval PCCRCs was possible missed lesion with adequate examination (73.6%); they were more often diagnosed at an advanced stage (stage III/IV; 53.2%) compared with non-interval type A (15.9%; P<0.001) and non-interval type B (40.9%; P=0.03) PCCRCs. The 3-year PCCRC rate was low in this FIT-based CRC screening program. Approximately half of PCCRCs were interval PCCRCs. These were mostly caused by missed lesions and were diagnosed at a more advanced stage. This emphasizes the importance of high quality colonoscopy with optimal polyp detection.

TOWARDS GROWTH-FOCUSED PHYSICAL ACTIVITY: QUALITATIVE EVALUATION OF A BETTER FUTURE

https://youtu.be/3xvOOk9vfEQ BACKGROUND Physical activity promotion has traditionally centered on weight loss, contributing to harmful practices and missed opportunities to do good. This study emphasizes the multifaceted benefits of physical activity beyond weight loss. The objective is to provide evidence for a growth-focused approach that will hopefully encourage more successful referral networks between clinical practice and health fitness professionals. METHODS Qualitative data were gathered through questionnaires from participants in 1:1 personal training and fitness classes. Questions included intended goals of participation, what they were able to accomplish, what aspects were most enjoyable and provided the greatest benefit, what may have exceeded their expectations, a single word to describe the experience, feedback about the instructor, and what they would tell someone who is considering participation. RESULTS Qualitative findings revealed that participants responded positively to the growth-focused approach, expressing increased enjoyment and adherence to sustain physical activities. Social connections formed during group activities emerged as significant contributors to sustained engagement, along with the instructor’s support and structure throughout the process. Data showed improvements in overall mental well-being, reductions in stress levels, increased fitness knowledge, self-efficacy, adherence, strength, conditioning, and mobility. CONCLUSIONS This study advocates for a shift in physical activity promotion, moving away from a weight-centric model towards a growth-focused approach. The positive reception and sustained engagement observed among participants suggest that emphasizing well-being, mental health, social connections, and overall growth can be effective in encouraging regular physical activity. This approach has the potential to contribute to a more positive and sustainable health and fitness culture. Future interventions and public health campaigns should encourage continued collaboration between clinical practice and health fitness professionals.

Transposon Removal Reveals Their Adaptive Fitness Contribution.

Transposable elements are molecular parasites that persist in their host genome by generating new copies to outpace natural selection. Transposable elements exert a large influence on host genome evolution, in some cases providing adaptive changes. Here we measure the fitness effect of the transposable element insertions in the fission yeast Schizosaccharomyces pombe type strain by removing all insertions of its only native transposable element family, the long terminal repeat retrotransposon Tf2. We show that Tf2 elements provide a positive fitness contribution to its host. Tf2 ablation results in changes to the regulation of a mitochondrial gene and, consistently, the fitness effect are sensitive to growth conditions. We propose that Tf2 influences host fitness in a directed manner by dynamically rewiring the transcriptional response to metabolic stress.